http://support.lenovo.com/hu/en/products/laptops-and-netbooks/thinkpad-t-series-laptops/thinkpad-t400


also see end of life url (for t400):
https://download.lenovo.com/eol/index.html

for linux see wiki: https://wiki.archlinux.org/index.php/Lenovo_ThinkPad_T400s

